I know this is going to sound like some clickbait bullshit title, but I'm genuinely curious, asking in good faith. My two oldest sons are enamored with him, and he seems like a genuine guy, so I'm asking - is he a nice guy? If you google the question, you get a bunch of reddit hate, which I don't always trust, because...it's reddit. I have not watched much content (not my thing, I'm old) but I'm just curious what the fediverse has to say.
he seems mostly well-intentioned, and probably won't be a terribly bad influence on your kids, moreso than any other algorithm slurry youtube videos, so on that scale he's probably fine for your kids to watch
if we were trying to assess his overall morality it would get into "is clickbait millionaire philanthropy an ethical way to spend your wealth" territory, which is a huge can of worms that's difficult to find a solid answer for